Radiological explorations in pediatric dentistry
1.Introduction
Radiological exploration, in dental medicine, in addition to its forensic nature, represents a key element in the success of our daily practice.
Good treatment necessarily results from a good diagnosis. Maxillofacial imaging is an essential tool to enable this good diagnosis; it must nevertheless be preceded by a complete clinical examination which allows to guide towards the type of imaging to be carried out.
It is essential for establishing the treatment plan by eliminating contraindications and guiding the therapy.
2. Interest of radiological imaging
Radiology allows us to :
- Guide the practitioner in his diagnosis for the detection of oral pathological conditions (cavities or trauma for example);
- Check the different sets of teeth for the detection of developmental anomalies, Control and management of eruption problems, evaluation of growth problems and orthodontic monitoring;
- Assist the practitioner in setting up an appropriate treatment plan;
- Monitor the therapies implemented for a post-operative evaluation of the different therapies in pediatric dentistry.
3. Radiological technique
The formation of the image is done schematically in four stages within a radiological chain:
- X-ray production;
- Formation of the radiant image: modulation of the X-ray beam by crossing the object;
- Detection of the radiant image: collection on a detector (analog or digital) of the radiant image;
- Presentation of the final image.
Radiological explorations in pediatric dentistry
4. The different radiographic imaging procedures
4.1. Two-dimensional radiographs:
4.1.1. Exo-oral radiographs:
4.1.1.1 Panoramic radiography:
Panoramic radiography, or orthopantomogram, is one of the extraoral dental radiography techniques. It allows to obtain an image of the dental arches as well as the surrounding structures on a single film thanks to a low exposure (0.006 mSv). In addition to the clinical examination, the orthopantomogram is a fundamental first-line examination when there are warning signs. It is this which allows to best assess the normality of the dentition.
- In orthodontics: it is considered:
– For the analysis of needs in interceptive or curative orthodontic treatment. It is necessary at least once in mixed dentition to check the presence of all germs and anticipate an orthodontic problem.
– After the age of 3 years, it can be considered in the event of ectopic dental position, abnormality in number or eruption.
– In case of suspicion of a problem with the eruption of the maxillary canines (if palpation of the vestibule has not revealed the submucosal presence of the maxillary canines around 11 years of age).
– In case of severe decay of the first permanent molars to observe the presence of germs of the third molars which will influence the orthodontic treatment plan.
- In cariology: in mixed and adult dentition, it can replace retro-coronal control radiographs if several carious lesions have been highlighted in different quadrants during the clinical examination.
- In pathology: if there is suspicion of extractions in a poly-carious context. It is possibly supplemented by retro-alveolar radiographs depending on the radiographic diagnosis.
- In traumatology: it is performed when the shock has resulted in a limitation of the mouth opening, Look for a crack, or even a fracture of the tooth; or an associated bone lesion.
The advantages of this type of imaging are:
- It allows a global view of all the anatomical elements;
- The possibility of making a bilateral comparison;
- Achievable at low cost;
- Minimal exposure to RX.
On the other hand, the panoramic has several limitations:
- This is a 2D exploration;
- Presence of coronal superpositions and projection of maxillary sinus cavities which can, respectively, prevent the detection of caries and create a false image of periapical bone lesion;
- Unreliability of size, location and shape of generated images: pantomographic technique generates vertical and horizontal distortions leading to dimensional distortions and variable overall magnification;
- Provides insufficient information on ectopic or impacted teeth.
- Teleradiography:
Skull X-rays provide a complete image of the skull from the front and side.
There are several implications:
Radiological explorations in pediatric dentistry
They are systematically considered as part of orthodontic treatment, in addition to panoramic radiography, when this treatment must be started at the end of the mixed dentition or in young adult dentition. They are essential for cephalometric analysis.
This X-ray examination allows:
- To examine the architecture of the skull, face and jaws with precision.
- To estimate the effect that growth will have on the evolution of the case and then monitor the growth of the face and jaws,
- To check the results of the treatment regarding the correction of the discrepancy between the jaws and the modification of the dental axes.
- To detect cranial malformations and traumatic processes.
- Intraoral X-rays:
- Retroalveolar radiography
A fundamental technique in dental practice, retroalveolar imaging provides the practitioner with essential information on a daily basis on the anatomy of the roots, canals and apices, as well as on the alveolar bone, the lamina dura and the desmodontal space. The retroalveolar image is a radiological projection on a small film allowing a detailed study of a tooth and its environment.
It is indicated:
- In conservative dentistry: These X-rays are used in addition to retro-
Coronaries on teeth with severe caries (significant coronal decay,
pulpo-periodontal damage….) to provide information on:
– possible pulp involvement and pulpo-periodontal complications.
– the physiological stage of the tooth or on the temporary tooth/underlying germ ratio
in order to make the right therapeutic decision.
- In traumatology: they are essential for:
– Look for a root fracture line.
– Observe periodontal damage.
– Assess post-traumatic complications.
– follow traumatized teeth.
- Others: They replace retro-coronary procedures when they are not feasible.
They can also be used for:
– The performance and monitoring of pulp treatments carried out after carious damage,
traumatic or otherwise.
– Monitor the delay in the development of a temporary or permanent tooth.
– Diagnosis and treatment of dental anomalies, etc.
This type of X-ray is done in two methods:
- By the technique of parallelism: The director beam is perpendicular to the axis of the tooth and to the plane of the film. The film is secured to the tube by a guide rod, which ensures perfect orthogonality between the beam and the film.
- By the bisector technique (Dieck method): The director ray must be perpendicular to the bisector plane of the angle formed by the axis of the tooth and the axis of the film.
Radiological explorations in pediatric dentistry
The advantages of retro-alveolar radiography:
- The technique is simple to use;
- Retro-alveolar images combine precision, sharpness and faithful measurement, without distortion.
Disadvantages of retroalveolar radiography:
- The field of exploration being limited to the size of the film;
- Correct placement of the film, made difficult in children, patients with small mouth opening;
- This technique may cause a gag reflex or soft tissue pain, particularly in the floor of the tongue.
- The retro-coronary shot (Bite-wing):
The retro-alveolar image is a radiological projection on a reduced-size film.
To successfully take this X-ray, the film is placed behind the temporary molars and the cone is oriented perpendicular to the film.
– These images improve the detection of proximal caries and hidden occlusal caries in addition to the clinical examination.
- The occlusal bite:
This is a second-line image which allows the anteroposterior and transverse situation to be clarified.
– The film is placed in the patient’s mouth with the head straight, or flexed or deflected.
– The source’s directing ray is orthogonal or oblique to the film axis.
Radiological explorations in pediatric dentistry
It can be carried out in the following cases:
- In mixed dentition, between 8 and 10 years, to assess root maturation, control the presence of germs and the eruption of permanent teeth (delayed eruption).
- Delayed eruption of permanent teeth.
- Number anomalies (suspicion of supernumerary and/or impacted teeth),
- In traumatology, it can be used to highlight suspected fractures of the mandible and/or condyles (all types of teeth).
- The limits of 2D radiography
Two-dimensional radiography has several disadvantages, namely:
- A deformation, resulting from the conical projection geometry;
- A lack of sharpness;
- A complexity of reading, due to the superposition on the same plane, that of the film, of structures which, at the level of the subject, belong to different planes (spatial summation).
4.2. Three-dimensional radiographs:
Also called 3D imaging or three-dimensional imaging, today it mainly includes computed tomography (CT) and cone beam computed tomography of the face (CBCT or cone beam CT).
These examinations are still considered today as second-line examinations, which follow conventional preliminary explorations, for the moment much less irradiating and often sufficiently contributive. A gradation of examinations according to increasing dosimetry is necessary.
This type of radiological examination is indicated when the information provided by the clinic and 2D radiology is not sufficiently contributory to the diagnosis and therapy and a 3D image is essential.
Interest in 3D imaging
- Refine the diagnosis in cases of trauma, particularly in the presence of root fractures.
- Facilitate certain complex surgical cases;
- Carry out the topographical and morphological study of included dental elements or a three-dimensional cephalometric study;
- Perform the preoperative examination in the presence of supernumerary germs, the planned avulsion of included or disincluded teeth in order to assess their situation in relation to other anatomical structures;
- Confirm extensive infection with significant radiolucent lesion related to different anatomical structures;
- Determine the origin of a maxillary cystic lesion;
- To assess the extent and ratios of maxillary tumor lesions.
4.2.1. The Cone-beam:
Cone beam computed tomography is an imaging method that uses computer technology to convert two-dimensional images into a three-dimensional (3D) image. As the name suggests, it uses a cone-shaped irradiation beam.
4.2.2. Computed tomography
The dentascanner or dental scanner is a classic scanographic examination.
The images are acquired in millimetric and volumetric form by computed tomography (X-rays).
After acquisition, reconstruction software is used, allowing the analysis of the dental and mandibular arches, in order to provide anatomical and pathological information.
CT scanning is reserved for people with multiple trauma, disabilities and for exploring malignant facial tumors.
5. Radioprotection
The X-ray examination must be done with protective measures because children are more sensitive to ionizing radiation than adults.
In order to limit the risk as much as possible, it is recommended to:
– Protect the small patient with a lead apron;
– Have the child wear a thyroid collar in case of exposure of the thyroid gland;
– Reduce exposure by 50% compared to that of adults in very young children (0 to 3 years)
and by 25% for subjects aged 3 to 15 years.
Radiological explorations in pediatric dentistry
6. Conclusion
Currently, precise knowledge of the different imaging techniques at our disposal seems essential to be able to extract the information necessary for establishing a diagnosis and/or quality therapeutic monitoring. An increasing demand for quality imaging seems to be a common demand for all practitioners.
Heraclitus said: “Nothing is, everything becomes”
The mistake to avoid for each of us would be to remain motionless, satisfied with our therapeutic method. Nothing like falling into boredom and our cases into relapse.
The world is changing, dental arches are changing, orthodontics is changing. Don’t stay fixed and find your happiness in change.” Julien Philippe.
Good oral hygiene is essential to prevent cavities and gum disease.
Regular scaling at the dentist helps remove plaque and maintain a healthy mouth.
Dental implant placement is a long-term solution to replace a missing tooth.
Dental X-rays help diagnose problems that are invisible to the naked eye, such as tooth decay.
The dentist uses local anesthesia to minimize pain during dental treatment.